Multi-mode sensors have become an important component in precision-guided munitions. To ensure accuracy and proper target acquisition, it has become increasing more useful to have multiple ways of detecting and tracking a potential target.
One common example of a multi-mode device is a missile seeker that combines mid-wave infra-red imaging capability and semi-active laser detection and tracking. The infra-red allows for tracking based on emitted heat or expected heat signature of a target, while a semi-active laser (SAL) detector allows the munition to home in on a target being ‘painted’ with a laser spot. The combination of the two creates a more robust and fault-tolerant seeker system that is less likely to be confused by counter-measures and capable of proving greater accuracy and operating in a wider range of environments.
With all of these advantages, there come several downsides to a multi-mode detector device. Generally, such devices require two disparate sensor systems whose outputs are combined and analyzed to give a true multi-mode detection capability. This causes such systems to generally be costly and complicated, limiting their use in the field. A multi-mode detection system that could take advantage of common components to provide multi-mode detection data from a single set of optics and detection components would offer the combined benefits of simplicity and cost reduction. A simpler device with fewer components is less likely to break or malfunction, and a lower-cost device can be more broadly applied. This is especially true in the realm of guided munitions, where the entire device is meant for single use in a high-impact operating environment. The advantages of a cheaper, simpler multi-mode detector for such applications should be readily apparent.